I have a fair amount of experience with the PSoC 3 and PSoC 5 as we use both of these in our products. Our products provide both a pin selectable bootloader and a 10 pin header to allow our customers to update the firmware and allows me to perform in circuit debugging.

OK, that said. What is needed to perform in circuit programming and debugging of a PSoC 1? We are considering using the PSoC 1 in a new device we are developing. It is a simple signal generator using a Silicon Labs Si5351 and we need a micro processor to control it. Why the PSoC 1? I may be wrong but it appears the PSoC 1 is the only version of PSoC that comes in an 8 pin dip. The device is a kit the customer builds and the 8 pin dip is very easy for the customer to install. The particular version of the chip is the CY8C27143.

Cypress say the following :We kindly mention that irrespective of the number of pins if any of the part that has ISSP_SCLK and ISSP_SDATA , you can program the part using Miniprog 3. The 8 pin CY8C27143-24PXI device actually has ISSP pins. So you can program the chip using Miniprog 3. Please go through Miniprog 3 user guide obtained from the link below which says that it can support ISSP programming also. Here is the manual for the MiniProg3. http://www.cypress.com/file/44091/download